If dirt were to turn today, a new development on the Ford plant site in St. Paul would have a marginal effect on the city's financial bottom line, according to a preliminary analysis.

None of the five proposed redevelopment scenarios for the 135-acre site in Highland Park would generate large increases -- or decreases -- to the tax base.

That was determined by a formula that uses the best guesses on current market conditions to show how a development might affect the budgets of the city and school district. The city's planning staff, and Hennepin County staff serving in a consulting role, made the analysis, considered an early projection that is expected to change in coming years as market conditions fluctuate.

The formula looks at the difference between city spending on services, such as parks and recreation or fire inspections, and city revenue, such as property taxes and other fees.

"This is one analysis of many we're doing," said Luis Pereira, a planner with the city. The findings were presented at a community meeting Monday night.

New development brings new income for a city, but it also costs more in services. According to the recent financial analysis, the five scenarios would affect the city in a range from a $5,000 deficit in the general fund to a $165,000 addition. Those amounts are a small fraction of 1 percent of the general fund.

Ford announced in 2006 that it would shutter the plant in 2008. But the plant, which has sat on the bluffs of the Mississippi River for more than 80 years, will stay open until 2011.

That has given a task force charged with studying the best reuse of the land a bit of a breather, but other studies -- effects on traffic, air pollution and storm-water flow -- continue. The extended timeline also means that the numbers in the financial-impact analysis are likely to change.

In 2007, the task force settled on five scenarios. They include recycling the land for industrial use, developing an office park, building a mix of low- to higher-density residential buildings and creating a technology and light-manufacturing center. The plans are projected to bring between 1,300 and 6,500 jobs.

Ford will have the final say on who buys the plant. Officials with the automaker, however, have worked closely with the city, which will impose zoning changes to accommodate redevelopment at the site.

St. Paul officials have called for proposals that take into account traffic, tax revenue, public transit and jobs.